Manusmriti
चतुरः प्रातरश्नीयात् पिण्डान् विप्रः समाहितः । चतुरोऽस्तमिते सूर्ये शिशुचान्द्रायणं स्मृतम् ॥ २१९ ॥
If a Brahmana, with concentrated mind, eats (during a month daily) four mouthfuls in a morning and four after sunset, (that is) called the lunar penance of children.
english translation
caturaH prAtaraznIyAt piNDAn vipraH samAhitaH । caturo'stamite sUrye zizucAndrAyaNaM smRtam ॥ 219 ॥
hk transliteration by Sanscript